Archive:000/Solar power: Difference between revisions

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Elie moved page Solar power to Archive:000/Solar power without leaving a redirect: Huge_refactor
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==Types==
==Types==
* [[Photovoltaics]] (PV) (solar panels) - generate electricity
* [[Photovoltaics]] (PV) ([[solar panels]]) - '''most common type''' of solar power
* [[Solar thermal panels]] - use sunlight to directly heat air or water, without involving electricity
* [[Concentrator photovoltaics]]
* [[Concentrated solar]] - produce high heat by focusing enough sunlight into one area. The heat can be then used for generating electricity or for industrial processes.
* [[Solar thermal panels]] - {{light|use sunlight to directly heat air or water, without involving electricity}}
<!-- TALK: maybe also mention here:
* [[Concentrated solar thermal]] - {{light|produce high heat by focusing enough sunlight into one area. The heat can be then used for generating electricity or for industrial processes.}}
  * combined photovoltaic+thermal panels
<!-- TALK: maybe also mention here: combined photovoltaic+thermal panels -->
  * concentrator photovoltaics, distinct from concentrated solar heat
-->


==Scenario==
==Viability==
Solar power could potentially provide most of the world's energy and '''replace [[fossil fuels]]'''. The [[land]] usage would be very small,<!--TODO: add calculation--> and [[rooftop solar]] could provide the majority of energy. However, this comes with some major challenges:
It's ''possible'' for solar power to provide most of the world's energy and '''replace [[fossil fuels]]'''. The [[land]] usage [[:File:solar-land-requirements.png|would be moderate]], and [[rooftop solar]] could be the main source.<!-- TALK: issue: the map estimates a much higher land requirement than the rooftop solar page does. There are some reasons for this (not terrible reasons), but it needs to be addressed/explained somewhere on the wiki. --> However, this comes with some major challenges:


===[[solar challenge 1|Challenge #1:]] Low-environmental-impact solar panels===
===[[/challenge 1|Challenge #1:]] Low-environmental-impact solar panels===


Currently, the most popular types of solar panels involve [[solar panel minerals|too many rare minerals]]. We couldn't scale them up enough even if we tried - there simply aren't enough of certain minerals in the Earth that can be mined. Mining also comes with environmental destruction and in some cases, child labor. <!-- maybe also mention that [[solar panel recycling]] is extremely limited and who knows if it'll get any better for the current wave of photovoltaics--> <!-- maybe also mention the good: the [[energy payback]] of solar panels is reasonable -->
Currently, the most popular types of solar panels involve [[solar panel minerals|too many rare minerals]]. We couldn't scale them up enough even if we tried - there simply aren't enough of certain minerals in the Earth that can be mined. Mining also comes with environmental destruction and in some cases, child labor. <!-- maybe also mention that [[solar panel recycling]] is extremely limited and who knows if it'll get any better for the current wave of photovoltaics--> <!-- maybe also mention the good: the [[energy payback]] of solar panels is reasonable -->
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# We need to be able to create [[rooftop solar|approximately 375,000 km^2]] of solar panels globally, without exceeding the reserves of any minerals.
# We need to be able to create [[rooftop solar|approximately 375,000 km^2]] of solar panels globally, without exceeding the reserves of any minerals.
# If the solar panels still contain ''some'' scarce minerals, they need to be fully recoverable upon [[solar panel recycling|recycling]].
# If the solar panels still contain ''some'' scarce minerals, they need to be fully recoverable upon [[solar panel recycling|recycling]].
# The ''energy payback time''{{x|defined as: {energy needed to manufacture the panels} divided by {power output of the panels, averaged over the full day cycle}. But also, if recyclability is needed as per requirement #2 above, then the energy of recycling ''also'' has to be factored in.}} should be ''significantly shorter'' than the lifespan of the panels. {{x|i.e. for panels with a 30-year lifespan, they should pay back the energy in 4 years or less. Preferable a 1-year payback - which could very well be achieveable. The first solar panels would still have to be manufactured using fossil fuel energy. Eventually after getting the ball rolling, [[solar powered factories]] would be viable.}}
# The ''energy payback time''{{x|defined as: {energy needed to produce the panels, including all their primary materials} divided by {power output of the panels, averaged over the full day-night cycle}. But also, if recyclability is needed as per requirement #2 above, then the energy of recycling ''also'' has to be factored in.}} should be ''significantly shorter'' than the lifespan of the panels. {{x|i.e. for panels with a 30-year lifespan, they should pay back the energy in 4 years or less. Preferable a 1-year payback - which could very well be achieveable. The first solar panels would still have to be manufactured using fossil fuel energy. Eventually after getting the ball rolling, [[solar powered factories]] would be viable.}}
# The solar panels don't have to be particularly efficient. 8% efficiency would probably be good enough. {{x|Today's most popular rooftop solar panels are about 17% efficient but too mineral intensive. Half that efficiency might still be enough to meet energy demand including charging [[electric vehicles]]. If not, then more solar panels would have to be manufactured, which is likely still viable as long as requirements 1,2,3 are met.}}
# The solar panels don't have to be particularly efficient. 8% efficiency would probably be good enough. {{x|Today's most popular rooftop solar panels are about 17% efficient but too mineral intensive. Half that efficiency might still be enough to meet energy demand including charging [[electric vehicles]]. If not, then more solar panels would have to be manufactured, which is likely still viable as long as requirements 1,2,3 are met.}}


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Only a small fraction of energy demands must be truly [[baseload]] power.
Only a small fraction of energy demands must be truly [[baseload]] power.
[[Category:Energy sources]]